Control of chaotic advection for mixing system using universal motor

This study presents a method of chaotification of universal motor drive by selecting appropriate topology of the power circuit and suitably choosing values of circuit components for mixing application. The purpose of chaotification is to improve homogeneity in the mixture and to reduce consumption of time, cost and energy. In particular, the dynamic behaviour of a pulse-width modulation controlled chopper fed universal motor drive with diode bridge rectifier at the source side has been explored for the occurrence of chaos in the mixer motor. Performance of the drive has been investigated with two different topologies of the filter circuit. The first topology uses a capacitor filter after diode rectifier and the other includes an LC filter at the motor terminals along with source-side capacitor filter. A systematic methodology for selecting appropriate values of the filter circuit components has been proposed for imparting chaotic motion to the motor load system. A comparative study showing a range of load torque and speed for which sub-harmonic or chaotic speed oscillation occurs in the motor for both the topologies of filter circuit has also been presented. Computer simulations and results of laboratory experiment performed on a 0.5 hp, 1800-rpm universal motor validate the proposed design method of the motor drive for the better mixing process.